For nearly 125 years, Renault has been constantly seeking to innovate. Its inventions have stood the test of time and are still used even today with many people not even realizing it. Direct drive gearbox (1899), replacement of the hand crank with an electric starter (1909), rack and pinion mechanical steering (1950), the addition of the ‘5th door’ (1961), infrared keyless entry (1983), hands-free card (2000). All these and more are Renault patented designs. The All-new Megane E-TECH Electric – the first of Renault’s Nouvelle Vague – sees Renault still innovating. More than 300 patents have been lodged for the design of the vehicle and its platform, of which we have selected seven to explore in finer detail. For our sixth article, we catch up with Renault Engineering Expert in energy management for electric vehicles, Jean-Marie L’Huillier, who talks us through how he helped improve the range of electric vehicles in cold-weather thanks to an ingenious system that recovers heat from the electric battery and engine.

The All-new Megane E-TECH Electric can cover up to 470 kilometers on a single charge. A range that Renault engineers have sought to keep as stable as possible regardless of the season. First of all, thanks to a battery temperature regulation system. Warmed in cold weather by circulating hot water from the electric motor and cooled in hot weather by circulating cold water coming from the coolant system, the battery on the All-new Megane E-TECH Electric is always at the ideal temperature for optimal charging and range.

Renault engineers went one step further in optimizing the vehicle’s electric range, especially in winter, when the cabin also has to be heated even though temperatures are not ideal for energy storage and charge upkeep. A challenge that is compounded by the fact that an electric motor, unlike a combustion engine, does not produce enough heat to run a traditional heating system inside the cabin.

Jean-Marie L’Huillier and Robert Yu, Renault Engineering Experts in electric vehicle heat management, tackled the issue head-on!

’’Because the All-new Megane E-TECH Electric is meant for the open road, we have developed and patented a system capable of recovering heat generated by the battery and engine when they are being used intensively, like during a fast recharge or driving down the highway. The heat is then used to warm the cabin in order to optimize the vehicle’s range.”

Jean-Marie L’Huillier,
Renault Engineering Expert in electric vehicle energy management
 The advantages of this latest innovation

When the outside temperature drops below 10°C, the heat recovery system for the battery and the electric motor offers several advantages:

  • Heat recovery naturally lowers the temperature of both the battery and electric motor;
  • It takes two times less energy to heat the cabin than with a traditional heat pump;
  • The range increase on motorways can reach up to 9%.

A brand-new process

Get rid of the energy-hungry electrical resistors running off the battery to heat the cabin! Nonsense for an electric vehicle. The same can be said for the traditional heat pumps that are not efficient enough for long journeys on motorways. The latest-generation heat pump designed by Jean-Marie L’Huillier and Robert Yu is more efficient in recovering heat from the battery and electric motor to ensure a comfortable temperature for the car’s occupants while also minimizing the impact on the car’s range as much as possible.

Innovation that proves how improvements to EV range aren’t only achieved through ever larger batteries.

To find out more

Patent reference: 

  • System for heat recovery from EV battery and powertrain:
    Patent FR3075109 / EP3727910B1 – Inventors: Jean-Marie L’Huillier et Robert Yu

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